TY - JOUR
T1 - Al2O3/ZnO Heterostructure-Based Sensors for Volatile Organic Compounds in Safety Applications
AU - Lupan, Oleg
AU - Santos-Carballal, David
AU - Magariu, Nicolae
AU - Mishra, Abhishek Kumar
AU - Ababii, Nicolai
AU - Krüger, Helge
AU - Wolff, Niklas
AU - Vahl, Alexander
AU - Bodduluri, Mani Teja
AU - Kohlmann, Niklas
AU - Kienle, Lorenz
AU - Adelung, Rainer
AU - de Leeuw, Nora H.
AU - Hansen, Sandra
N1 - Funding Information:
Funding Project “SuSiBaBy”-SulfurSilicon Batteries by the EUSH and EFRE in SH (LPW-E/3.1.1/1801). Federal Ministry of Education and Research - “PorSSi” project (03XP0126 A & B). German Research Foundation (DFG, Deutsche Forschungsgemeinschaft) under the schemes SFB1261, SFB 1461 & AD 183/16-1. Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), Project-ID 434434223, SFB 1461. Grant G5634 “Advanced Electro-Optical Chemical Sensors” AMOXES, NATO Science for Peace and Security Programme (SPS). Additionally, the authors thank the WTSH and the EUSH for partially funding this project BAEW with (LPW-E/1.1.2/1486). A.K.M. acknowledges the UPES SEED grant (year 2022) for computations.
Funding Information:
Project “SuSiBaBy”-SulfurSilicon Batteries by the EUSH and EFRE in SH (LPW-E/3.1.1/1801). Federal Ministry of Education and Research - “PorSSi” project (03XP0126 A & B). German Research Foundation (DFG, Deutsche Forschungsgemeinschaft) under the schemes SFB1261, SFB 1461 & AD 183/16-1. Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), Project-ID 434434223, SFB 1461. Grant G5634 “Advanced Electro-Optical Chemical Sensors” AMOXES, NATO Science for Peace and Security Programme (SPS). Additionally, the authors thank the WTSH and the EUSH for partially funding this project BAEW with (LPW-E/1.1.2/1486). A.K.M. acknowledges the UPES SEED grant (year 2022) for computations.
Funding Information:
We acknowledge funding within the project “SuSiBaBy”-SulfurSilicon Batteries by the EUSH and EFRE in SH (LPW-E/3.1.1/1801). We are especially grateful to the Federal Ministry of Education and Research by funding the former “PorSSi” project (03XP0126 A & B). The membership of D.S.C. and N.H.d.L. of the UK’s HEC Materials Chemistry Consortium was funded by EPSRC (EP/L000202 and EP/R029431). This work used the ARCHER2 UK National Supercomputing Service ( http://www.archer2.ac.uk ). This work also used ARC4 resources, part of the High-Performance Computing facilities at the University of Leeds, United Kingdom. This work was in part funded by the German Research Foundation (DFG) under Grant KI 1263/17-1. This work was also funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), Project-ID 434434223, SFB 1461 and SFB 1261. A.K.M. acknowledges the SEED computational support from University of Petroleum and Energy Studies (UPES), Dehradun. All data created during this research are presented in this paper and in the Supporting Information . This research was sponsored in part by the NATO Science for Peace and Security Programme (SPS) within Grant G5634 “Advanced Electro-Optical Chemical Sensors” AMOXES.
Publisher Copyright:
© 2022 American Chemical Society.
PY - 2022/6/29
Y1 - 2022/6/29
N2 - Monitoring volatile organic compounds (VOCs) in harsh environments, especially for safety applications, is a growing field that requires specialized sensor structures. In this work, we demonstrate the sensing properties toward the most common VOCs of columnar Al2O3/ZnO heterolayer-based sensors. We have also developed an approach to tune the sensor selectivity by changing the thickness of the exposed amorphous Al2O3 layer from 5 to 18 nm. Columnar ZnO films are prepared by a chemical solution method, where the exposed surface is decorated with an Al2O3 nanolayer via thermal atomic layer deposition at 75 °C. We have investigated the structure and morphology as well as the vibrational, chemical, electronic, and sensor properties of the Al2O3/ZnO heterostructures. Transmission electron microscopy (TEM) studies show that the upper layers consist of amorphous Al2O3 films. The heterostructures showed selectivity to 2-propanol vapors only within the range of 12-15 nm thicknesses of Al2O3, with the highest response value of ∼2000% reported for a thickness of 15 nm at the optimal working temperature of 350 °C. Density functional theory (DFT) calculations of the Al2O3/ZnO(1010) interface and its interaction with 2-propanol (2-C3H7OH), n-butanol (n-C4H9OH), ethanol (C2H5OH), acetone (CH3COCH3), hydrogen (H2), and ammonia (NH3) show that the molecular affinity for the Al2O3/ZnO(1010) interface decreases from 2-propanol (2-C3H7OH) ≈ n-butanol (n-C4H9OH) > ethanol (C2H5OH) > acetone (CH3COCH3) > hydrogen (H2), which is consistent with our gas response experiments for the VOCs. Charge transfers between the surface and the adsorbates, and local densities of states of the interacting atoms, support the calculated strength of the molecular preferences. Our findings are highly important for the development of 2-propanol sensors and to our understanding of the effect of the heterojunction and the thickness of the top nanolayer on the gas response, which thus far have not been reported in the literature.
AB - Monitoring volatile organic compounds (VOCs) in harsh environments, especially for safety applications, is a growing field that requires specialized sensor structures. In this work, we demonstrate the sensing properties toward the most common VOCs of columnar Al2O3/ZnO heterolayer-based sensors. We have also developed an approach to tune the sensor selectivity by changing the thickness of the exposed amorphous Al2O3 layer from 5 to 18 nm. Columnar ZnO films are prepared by a chemical solution method, where the exposed surface is decorated with an Al2O3 nanolayer via thermal atomic layer deposition at 75 °C. We have investigated the structure and morphology as well as the vibrational, chemical, electronic, and sensor properties of the Al2O3/ZnO heterostructures. Transmission electron microscopy (TEM) studies show that the upper layers consist of amorphous Al2O3 films. The heterostructures showed selectivity to 2-propanol vapors only within the range of 12-15 nm thicknesses of Al2O3, with the highest response value of ∼2000% reported for a thickness of 15 nm at the optimal working temperature of 350 °C. Density functional theory (DFT) calculations of the Al2O3/ZnO(1010) interface and its interaction with 2-propanol (2-C3H7OH), n-butanol (n-C4H9OH), ethanol (C2H5OH), acetone (CH3COCH3), hydrogen (H2), and ammonia (NH3) show that the molecular affinity for the Al2O3/ZnO(1010) interface decreases from 2-propanol (2-C3H7OH) ≈ n-butanol (n-C4H9OH) > ethanol (C2H5OH) > acetone (CH3COCH3) > hydrogen (H2), which is consistent with our gas response experiments for the VOCs. Charge transfers between the surface and the adsorbates, and local densities of states of the interacting atoms, support the calculated strength of the molecular preferences. Our findings are highly important for the development of 2-propanol sensors and to our understanding of the effect of the heterojunction and the thickness of the top nanolayer on the gas response, which thus far have not been reported in the literature.
KW - Al2O3
KW - DFT
KW - gas response
KW - gas sensors
KW - heterojunctions
KW - semiconducting metal oxides
KW - VOCs
KW - ZnO
UR - http://www.scopus.com/inward/record.url?scp=85133214245&partnerID=8YFLogxK
U2 - 10.1021/acsami.2c03704
DO - 10.1021/acsami.2c03704
M3 - Article
C2 - 35704838
AN - SCOPUS:85133214245
SN - 1944-8244
VL - 14
SP - 29331
EP - 29344
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
IS - 25
ER -